Push-button structure



Nov. 17, 1953 E. H. ALLEN 2,659,236

PUSHBUTTQN STRUCTURE Filed 001;. 9, 1950 2 Sheets-Sheet 1 INVENTOR.54/24 H. ALLE/V Patented Nov. 17, 1953 PUSH-BUTTON STRUCTURE Earl H.Allen, Westfield, N. J., assignor to General Instrument Corporation,Elizabeth, N. J., a corporation of New York Application October 9, 1950,Serial No. 189,229

13 Claims.

The present invention relates to a novel construction for a pushbuttonof a type utilized for the tuning of radio sets, and in particular tosuch a construction which facilitates the setting of the pushbuttoncorresponding to a selected radio frequency and which renders thesetting, when once made, permanent until it is desired that it bealtered.

The pushbutton structure of the present invention is particularlydesigned for that relatively conventional type of pushbutton-actuatedmechanism in which an adjustable setting device is carried by oroperatively connected to the pushbutton itself. In tuning units of thistype, various expedients have been resorted to in order to release thesetting device so that its position relative to the pushbutton may bealtered, usually to correspond with the selected radio frequency towhich the unit has been manually pretuned, and then to firmly look thesetting device in that altered position, thereby permitting subsequentactuation of the pushbutton to tune the unit to the selected radiofrequency. It has proved to be highly desirable to control the lookingand releasing of the setting device through manipulation of thepushbutton itself, and preferably through motion of the pushbutton inthe same direction as the pushbutton is moved when the unit is to betuned.

In pushbuttons of this general type, the adjustable setting device is inthe form of a cam articulately mounted on a support which is in turnsuitably mounted for movement within the tuning unit. An auxiliarymember to which the pushbutton is secured is also movably mounted withinthe unit so as to move with the support and so as to have a limiteddegree of movement with respect thereto, the relative position of themovable support and the auxiliary member controlling the actuation of aclamp and causing that clamp to operatively engage or'disengage thesetting device and lock it in or release it from adjusted position. Whenthe setting device is locked in adjusted position, depression of thepushbutton causes the device to engage and move .a control element inthe tuning unit which is in turn operatively connected to the tuningcomponents, such as coils, condensers or the like. When the settingdevice is unlocked, depression of the pushbutton causes the device toengage said control element but in that case the setting device conformsto the preset position of the control element.

In the most convenient arrangement when the auxiliary m m e a r ing thpushbutton is outwardly positioned with respect to the movable supportthe adjustable setting device is unlocked. When so arranged, depressionof the pushbutton causes the movable support to be moved thereby withoutsubstantially altering its position relative thereto, so that thesetting device is positioned according to the tuned status of the unit.Thereafter, continued pressure upon the pushbutton in the direction ofits depression will cause the auxiliary member to move inwardly relativeto the movable support, thus actuating the clamp and loc ing the settingdevice in its newly adjusted position.

One problem which has arisen in the operation of pushbuttons of thistype is that, when the auxiliary member has been moved outwardly withrespect to the movable support so as to unlock the setting device,subsequent depression of the pushbutton causes the auxiliary member andthe movable support to change their relative positions before thesetting device engages the control element in the tuning unit, thuscausing clamping pressure to be exerted to a greater or lesser degreeupon the setting device before it can be positioned corresponding to thetuned status of the unit. In the present invention this defect iseliminated by providing structure which releasably holds the movablesupport and auxiliary member in extended position during initialdepression of the pushbutton. This structure is in the form of a springactive in a detent manner between the movable support and the auxiliarymember.

After the setting device, when unclamped, has assumed a positioncorresponding to the tuned status of the unit, further depressive forceexerted upon the pushbutton, is required in order to lock the settingdevice in position. In prior art devices it has been necessary to exerta sub stantial depressive force before the setting device is firmlyclamped to the movable support, and this often results in a dislocationof the tuned status of the unit which gives rise to decreased fidelityof reception. The desired relationship between setting device, clamp andaux-.- iliary member should be such that the exertion of but a slightforce upon the clamp by the auxiliary member will result in the exertionof suffioient pressure upon the setting device to firmly loci: it inadjusted position and thus prevent any additional pressure fromdislooating the position of the setting device or the control elementwith which it is engaged. However, the achievement of such a precise anddelicate relationship between the parts has not been realized in thepast, largely because of the necessary manufacturing variations in thesizes of the various component parts of the pushbutton. The tolerancesin fabrication of these parts cannot well be less than a few thousandthsof an inch, yet a few thousandths of an inch may make all the difierencebetween success and failure in the achievement of optimum operation. Ifthe parts are a trifle larger than normal and close control is sought,the setting device will not have sufficient freedom of motion on thesupport when it is presumably unlocked, and consequently dislocation ofthe tuned status of the unit will result. If the parts are slightlysmaller than normal, when the setting device is unclamped it will becompletely loose. This is not desirable because it might, by its ownweight, fall to an inoperative position. Moreover, if it is completelyloose there will be so much play between the auxiliary member and clampon the one hand and the setting device on the other that immediatelocking of the setting device as soon as the auxiliary member actuatesthe clamp will not take place.

According to the present invention, this defeet is eliminated throughthe provision, on the clamp, of an adjusting means, here shown as ascrew depending therefrom and engageable with the setting device, theadjusting means being manually adjustable to conform to and compensate'for the variations in size of the component parts of the unit, so thatonce a given group of parts have been assembled, the adjusting means maybe appropriately manipulated to take up all play in the clamp-settingdevice linkage. A further advantage of this arrangement resides in thefact that a controllable amount of pressure may be exerted upon thesetting device even when it is unlocked, so that it cannot accidentllymove to an inoperative position but is still substantially freelymovable to adjusted position when it engages the control element in thetuning unit.

Once the setting device has been locked in adjusted position, it isretained in that looked condition only so long as the auxiliary memberretains its inner position relative to the movable support. It oftenoccurs that, because of shock, vibration or the like, the auxiliarymember tends to move out of its inner position, and when this occurs thesetting device becomes unlocked and must be reset. When tuning devicesutilizing such pushbutton units are employed in vehicles this becomes avery significant problem, and when, as is often the case, the pushbuttonunits, after being depressed, are forced outwardly by means of a spring,the shock incident to the stopping of the pushbutton units in the outerposition also tends to cause movement of the auxiliary member to itsunlocking position relative to the movable support, it being rememberedthat in most cases that unlocking position is directed outwardly withrespect to the movable support, this being in the same direction as thesupport and the auxiliary member are urged by the spring. In the presentinvention, this defeet is eliminated by utilizing a spring active in adetent manner between the movable support and the auxiliary member so asto releasably retain the auxiliary member in looking position on thesupport. This spring is preferably the same one which releasably retainsthe auxiliary member in unlocking position with respect to the supportonce it is thus placed.

When, as is here specifically discl s d, h

auxiliary member is slidably mounted directly upon the support, it isnecessary for proper and eiiortless operation of the device that themember and support be retained in parallel slidable relationship. Thesame spring which acts to releasably retain the auxiliary member inlooking or unlocking position on the support also tends to retain theauxiliary member and support in parallel slidable relationship, thespring being mounted on one of the members or supports and engageablewith and movable over the other of the members or supports, said springexerting a resilient action therebetween to attain the desiredobjective.

Many modes of mounting the clamp on the support have been suggested, butall those simple enough for mass production permit some play or movementof the clamp with respect to the support even when the clamp is engagedwith the setting device. This is most undesirable, since such movementof the clamp often results in a corresponding movement of the settingdevice with which it is engaged, and this leads, as will be understood,to inaccuracy in tuning. To avoid this defect, a member is interposedbetween the clamp and the setting device, that member being rigidlymounted on the support in the direction of play of the clamp.Consequently, even if the clamp should move, the member directly incontact with the setting device will not move, and as a result theposition of the setting device on th support will not be dislocated. Inthe form here specifically disclosed the member which performs thisdesirable function is a leaf spring which tends to move the clamp tounlocking position, the setting of the adjusting screw carried by theclamp compensating therefor, the spring thus assisting in reducing playin the clamp-setting device linkage in the direction of motion of theclamp between clamping and releasing positions.

The pushbutton structure of the present invention is made of a pluralityof simple and easily constructed parts which lend themselves readily toproduction on a large scale and to ready assembly. Inexpensiveness ofmanufacture is facilitated by the fact that the adjusting device carriedby the clamp permits the use of reasonable manufacturing tolerances inthe dimensions of the parts.

To the accomplishment of the above and to such other objectives as mayhereinafter appear, the present invention relates to the structure of apushbutton unit as defined in the appended claims and as described inthis specification, taken together with the accompanying drawings inwhich:

Figs. 1 and 2 are side cross-sectional views of a portion of a tuningunit, disclosing the manner in which the setting device of the presentinvention, when locked, controls the tuning of the unit, Fig. 1 showingthe unit with the pushbutton in extended position and Fig. 2 showing theunit with the pushbutton in depressed position. In both Figs. 1 and 2the auxiliary member is in locking position relative to the movablesupport;

Fig. 3 is a top plan view of the pushbutton unit with the auxiliarymember in looking position and with the setting device locked;

Fig. 4 is a side elevational view of the pushbutton unit of Fig. 3;

Fig. 5 is a bottom plan view thereof;

Fig. 6 is a side cross-sectional view, taken along the line 6-6 of Fig.'7, of the pushbutton unit with the auxiliary member in unlockingposition and with the etting device unlocked;

Fig; 7 is a bottom plan view of the pushbutton unit of Fig. 6, thespring active between the movable support and the auxiliary member beingshown in phantom;

Fig. 8 is a view similar to Fig. 2, but showing the position which thevarious parts assume when the auxiliary member has moved from itsunlocking toward its locking position until it just makes contact withthe clamp; and

Fig. 9 is a side cross-sectional view of the pushbutton unit taken alongthe line 9-9-of Fig. 8.

As here specifically disclosed, the pushbutton unit comprises a movablesupport generally designated A on which a setting device generallydesignated B is pivotally mounted so as to assume a plurality ofpositions, a clamp C being mounted on the support A and movable betweena clamping position illustrated in Figs. 3-5 in which position it exertspressure upon the setting device B so as to lock it in adjustedposition, and a releasing position illustrated in Fig. 6, in whichposition the setting device B is unlocked so as to be relatively freelymovable on the support A. An adjusting means D is provided on the clampC so that the relative position of the clamp C, support A and settingdevice B can be controlled and fixed despite variations in thedimensions of the parts. An auxiliary member E is slidably mounted onthe support A so as to be movable relative thereto between an extendedunlocking position, in which the auxiliary member E and the clamp C aredisengaged, and a telescoped locking position, in which the auxiliarymember E engages the clamp C and moves it to its locking positionrelative to the setting device B. The operative engagement between theauxiliary member E and the clamp C is achieved by means of contactingsurfaces so oriented with respect to one another and so cooperative withthe setting of the adjusting means D that a firm locking action isexerted on the setting device B as soon as the auxiliary member E makescontact with the clamp C (see Figs. 8 and 9), the auxiliary member Ethen being further movable to its full locking position (see Figs. 3-5)50 as to intensify the locking action exerted on the setting device B.Resilient means F is active between the auxiliary member E and thesupport A so as to maintain those parts in parallel relationship, thesame resilient means F preferably being utilized to exert a detentaction effective to retain the auxiliary member E in its locking orunlocking position relative to the support A once the auxiliary member Ehas been thus positioned.

Turning now to the details of the embodiment here disclosed, the supportA is in the form of an elongated plate of metal or the like having anarrow forwardly projecting tongue 2, a slightly wider portion 4, awider and downwardly bent portion (5 defining shoulders 8, and acomparatively wide and substantially flat base H1 terminating in anarrow rear extension I2 having an end edge M. The rear extension I2 isprovided with a longitudinal slot I6 which is widened intermediate itslength at I8. A lateral groove 20 is formed on the underside of the rearextension 52 at an appropriate point along its length for apurpose'hereinafter to be disclosed.

A strip of emery paper 22 or other substance having a frictional surfaceis secured to the upper surface of the base ii) in any appropriatemanner, and the setting device B is placed thereover, a rivet 24 passingthrough apertures in the setting device B and the base l0 and beingsecured in place by being curled over at 26 on the underside ofv thebase II], the rivet 24 thus defining an axis about which the settingdevice B can pivot. The setting device B takes the form of asubstantially semi-circular metal cam M3 extending out to either side ofthat portion of the base H! to which it is secured so as to define apair of contact surfaces 30, 30. Projecting ears 3!, 3! are formedthereon to limit the degree of rotation of the cam 28 about the rivet24.

A U-shaped bracket generally designated 32 is secured to the upper sideof the base In rearwardly of the setting device B by means of rivets 34passing through the horizontal portion 35'thereof, those rivets alsoserving to secure a leaf spring 36 to the top of the horizontal portionof the bracket 32. The forward vertical arm 38 of the bracket 32 has aclosed-top aperture therethrough through which the end of the leafspring 36 may project so as to overlie the setting device B. The rearvertical part of the bracket 32 is defined by a pair of upstandinglaterally sepa' rated fingers 42, 42'.

The clamp C takes the form of a stiflly resilient strip having a body 44wider than the aperture 40 in the vertical portion 38 of the bracket 32and wider than the spacing between the bracket fingers 42, 42'. A tongue46 narrow enough to extend through the aperture 40 extends forwardlyfrom the body 44, said tongue 46 having a tapped aperture 48 therein. Adownwardly bent narrow portion 5|] extends rearwardly from the body 44and passes between the upstanding bracket fingers 42 and 42' and mergesinto a tail portion 52 terminating in a slightly upwardly bent lip 54.An adjusting screw 56, which defines the adjusting means D carried bythe clamp C, is threadedly received within the aperture 48 so as todepend from the tongue 46 and engage the tip of the leaf spring 3'6 overthe setting device B.

The device as thus for described is assembled by passing the tongue 46through the aperture 48, the adjusting screw 56 thereafter beingthreaded through the aperture 48 so as to press against the spring 36and setting device B and thus lift the tongue 46 until it engages theclosed top of the aperture 40, the clamp C thus pivoting about saidclosed top as a fulcrum until the tail 52 makes contact with therearwardly extending support portion 12 which it overlies. Since the topof the screw 56 projects above the tongue 48, the clamp C can no longerbe withdrawn from the aperture 40, and it is therefore restrained fromundue rearward movement. Since the body 44 of the clamp C is wider thanthe aperture 40,

undue forward movement of the clamp C is prevented and the clamp is thusreleasably secured to, and is pivotable on, the support A.

The auxiliary member E comprises a body portion 58 adapted to slide overthe upper surface of the rear support portion l2, the body portion 58having depending rails 60, 60' on either side thereof to encompass theside edges of the rear support extension i2. A tail 62 preferablyintegrally formed with the body portion is adapted to receive apushbutton 64 thereover, the pushbutton being retained in positionthereon by means of notches 6G. The central forward portion of the body58 is cut away at B8 and a T- shaped lug 18 extending below the bodyportion 58 and preferably integral therewith i connected thereto bymeans of an upwardly projecting connecting portion 12 which defines acam surface. The head of the lug ii! is adapted to pass through the wideportions l8 of the slot [6 in the rear support extension !2, and thebody of the lug 10 is narrower than theslot It so that attests 7 the hisis slidable therealong. the length of he slot 45 thus l m in he degreeof. l a-bili y o th uxi i y em er E with. spe t support A- Once the lug1D has been passed through the slot [6 so as to mount the auxiliarymember E on the support A, the resilient means F is engaged between thesupport A and the head of the lug 10. This means takes the form of aleaf spring having a body 14 and a pair of forwardly projecting arms 1G,16, notches 18, I8 (see Figs. 5 and 7) being iormed between the arms 16,15' so that the resilient means F may be engaged with that portion ofthe lug It which projects downwardly below the support A. When theresilient means F is secured in position it will assume a bowed shape asmay best be seen from Figs. 4, 6 and 9, the arms T6, 16' engaging theunderside of the support A inwardly of the lug 10 and the body portion14 engaging the underside of the support A cutwardly of the lug 10, theresilient means F tendto pull the lug l downwardly through the slot iand thus tending to retain the auxiliary member E parallel with the rearsupport extension l2 on which it is mounted.

Since the resilient means F is positively secured to the lug ID, it ismovable with respect to the support A along with the auxiliary member E.It therefore may function as a detent mechanism to hold the auxiliarymember E in predetermined positions. To this end, that portion of thebody 14 which engages the underside of the support A is rather sharplybent, as at 80, the bent portion 80 being received into the slot 20 inthe underside of the support A when the auxiliary member E is telescopedwith respect thereto (see Fig. 4), and snapping around the end edge I4of the rear support extension 12 when the auxiliary member E is extended(see Fig. 6) As a result of this spring detent action the auxiliarymember E will be releasably retained in its telescoped or extendedpositions, but can be moved from those positions upon the application offorce thereto solely in the direction in which it is desired that it heslid.

The pushbutton unit of the present invention is adapted to be used in atuning unit schematically shown in Figs. 1, 2 and 8. The unit maycomprise an inner wall 82 and an outer wall 84 between which a rotarycontrol element 86 is mounted, that element being connected to thetuning components of the unit in any desired manner. The element. 86 iscentrally apertured at 88, the inner wall 82 is apertured at 90 and theouter wall 84 is apertured at 92. The support A is slidably mountedbetween the walls 82 and 84 with its body portion l0 slidable throughthe aperture 92, its narrow forward portions 2, 4 and 6 slidable throughthe aperture 88, and its forward portion 2 slidable through the aperture90. A spring 94 is active between the inner wall 82 and the shoulders 8on the support A so as to urge the pushbutton unit outwardly, anupwardly projecting lug 96 on the support A limiting its outward mot on.

When the auxiliary member E is telescoped with respect to the support A,so that it assumes the position shown in Figs. 1-5, the cam 12 on theauxiliary member E engages and lifts the tail 52 of the clamp C, thuscausing that clamp to pivot 3.21. fiQQQ Q'Q- K Q ii tiqll 3 d. Fig, s soas to force the screw 56 aga ns the spring 36 and toward the settingdevice B, thus thetisettine device B, against the emery strip. with.considerable and. locking force and preventing. pivotal motion of thesetting device B iromitsadjustedposition. When the pushbutton 64 isdepressed from the position of. l to the position of Fig. 2; the settingdevice B will be moved inwardly until its contact surfaces 30, 30engagethe rotatable control element 86 and cause that element to assumea rotative positioncorre, sponding exactly to the position of thesetting device B on the support A. In this manner the tuning; unit. istuned to a predetermined frequency corresponding to the fixedposition ofthe setting device B whenever the pushbutton 54. is depressed.

It will bev noted. that when the pushbutton Ii is released the spring 94forces the entire unit outwardly until the. lug 96' on the support A.en.- gages thev outer wall 84, at which time outward motion of the.pushbutton is abruptly stopped. The attendant shock, and the inertia ofthe push- .button 64 and. the auxiliary member E, will tend to cause theauxiliary member E to move outwardly with respect to the support A. Thistendency is, however, effectively prevented by the detent engagement ofthe bent portion of the resilient member F in the groove 20 on theunderside of the rear support extension 12.

When it is desired to adjust the position of the setting device B, it ismerely necessary to grasp the pushbutton 34 and pull it outwardly beyondits position shown in Fig. 1. The resilient mea s F is so calibratedthat a maximum pull of 7 pounds will cause the bent portion 80 of theresilient means F to disengage from the slot 20 on the support A andwill permit the auxiliary member E to be extended with respect to thesupport A, the lug Ill sliding within the slot I6 and carrying theresilient member F along therewith, until the lug 10 reaches the outerend of the slot it (see Figs. 6 and '7) In this position the bentportion 80 of the resilient member F snaps around the rear edge [4 ofthe rear support extension l2 and thus releasably retains the auxiliarymember E in its extended position.

In this position, the cam 12 is disengaged from the tail '52 of theclamp C, and the clamp C will then assume the position shown in Fig. 6,unlocking the setting device B. As has been previously set forth, it isimportant that as little play as possible exist between the clamp C andthe setting device B when the setting device is lin locked, in orderthat the setting device B should not tumble to an inoperative position,and in order that it may be positively locked at the earliest possiblemoment after it has been reset to desired position. The spring 36 tendsto pivot the clamp C in a clockwise direction as viewed in Fig. 6 untilits tail 52 engages the upper surface of the support A. For bestoperation, and in order to compensate for slight variations in thedimensions of the various parts, the screw 56 is initially adjusted uponassembly of the device so that, with the parts in the position shown inFig. 6, a very slight pressure will be exerted upon the setting deviceB. It has been found very suit able to adjust the screw 56 so that atorque of no more than 1 inch ounce would be required to pivot thesetting device B about the rivet 24. Because of the use of the adjustingscrew 56, this t g be accurately achieved. in every unit, althou h theparticular position of the screw 56 will vary from unit to unitdepending upon variations in dimensions of the parts thereof. Once agiven unit 9 has been thus adjusted, a drop of cement may be appliedaround the threads on the screw 56 so as to fix its position.

In order to readjust the position of the setting device B on the supportA once it has been unlocked, the tuning unit is first manually tuned sothat the rotatable control element 86 will assume a given position, suchas the position shown in Fig. 8. Then, while the auxiliary member Eremains in extended and unlocking position with respect to the supportA, retained in that position by the detent action between the bentspring portion 80 and the end support edge M, the pushbutton 64 isdepressed, thus carrying the support A and the setting device B alongtherewith. This time, since the setting device B is comparatively freeto pivot about the rivet 24, the setting device B will assume theposition of the rotatable element 86, thus preconditioning thepushbutton unit to tune the device to the frequency in question wheneverthat pushbutton is later depressed.

After the setting device B has assumed the rotative position of theelement 86, continued I inward pressure on the pushbutton 64, on theorder of 8 pounds maximum, will disengage the bent spring portion Bl]from the end support edge is and permit the auxiliary member E totelescope with respect to the support A. The abovementioned force issufficiently smal1 so that the application thereof to the setting deviceB and the control element 8'6 will not cause dislocation of theirrotative positions. The above-named force is, however, sufiicientlygreat so as to prevent the auxiliary member E from beginning totelescope with respect to the support A before the setting device B hasassumed its desired position corresponding to that of the pre-setcontrol element 86.

As the auxiliary member E telescopes with re-- spect to the support A,the cam 12 carried thereby will engage the upwardly curled tip 54 of thetail 52 on the clamp C and will tend to cause that clamp to pivot in acounter-clockwise direction (see Figs. 8 and 9). Since the screw 56 hasalready been adjusted to take up all play between the clamp C and thesetting device B, even the slightest cam action exerted on the tip 54 bythe cam 12 will cause the clamp C to press down firmly on the settingdevice B, and to a sufiicient degree to positively lock the settingdevice B in adjusted position. It will be noted that this positive lockis achieved even though only slight pressure is applied to the clamp C,and this because of the prior adjustment of the screw 56. Thereafter,the exertion of continued inward pressure on the pushbutton 64 will movethe auxiliary member E to fully telescoped position (see Figs. 3-6)bending the clamp C and increasing the clamping force exerted on thesetting device B. While thismay require the exertion of appreciableforce on the pushbutton 64, that force being necessarily transmitted tothe setting device B, dislocation of the setting device B cannot takeplace because it has already been firmly clamped in position by theinteraction between cam 12 and lip 54.

Because of the simple manner in which the clamp C is manufactured andassembled in operative position on the support A, appreciable freedom oflateral movement thereof is possible. However, because the spring 36 isinterposed between the screw 56 and the setting device and has nolateral play, any such lateral motion of the clamp C willnotbe'transmitted to the setting setting device B will not be dislocatedthereby.

The construction here disclosed therefore produces a pushbutton unitwhich functions more accurately and positively than prior artstructures, the construction of which is simple and inexpensive, andwhich does not require the maintaining of precise tolerances inmanufacture.

Although but a single embodiment 'of the present invention is herespecifically disclosed; it will be apparent that many variations may bemade therein, all within the spiirt of the invention as defined in thefollowing claims.

I claim:

1. In a tuning structure for a radio set, a movable support, anadjustable setting device articulately mounted thereon, a clamppivotally mounted on said support, one end of said clamp being directedtoward said setting device, a screw adjustably threadedly received insaid end, extending. therefrom toward said setting device, and adaptedto exert locking pressure on said setting device when said clamp isappropriately moved, a leaf spring mounted on said support and having aportion interposed between said screw and said setting device, saidspring being biased to urge said screw away from said setting device,and an auxiliary member including a pushbutton operatively connected tosaid clamp and effective, when said auxiliary member is moved in a givendirection with respect to said support, to force said clamp to move onsaid support in a direction such as to press said screw toward saidsetting device against the action of said leaf spring and lock saidsetting device in adjusted positionsaid screw being adjustable to varythe degree to which it depends from said clamp so as to regulate thepressure applied thereby on said setting device and so as to press saidleaf spring lightly against said setting device when said auxiliarymember is not moved in said given direction.

2. In a tuning structure for a radio set, a movable support, anadjustable setting device articulately mounted thereon, a clamparticulately mounted on said support, one end of said clamp beingdirected toward said setting device, a screw adjustablythreadedly'received in said end,.extending therefrom toward said settingdevice and adapted to exert locking pressure on said setting device whensaid clamp is appropriately moved, an auxiliary member including apushbutton slidably mounted on said support so as to be movable betweena locking position telescoped with respect to said support, in whichposition said auxiliary member is connected to said clamp, and anunlocking position extended with respect to said support, in whichpositionsaid auxiliary member is disconnected from said clamp, saidauxiliary member and said support defining relatively movable elements,a spring carried by one of said elements and engageable with the otherof said elements, said other of said elements havi ing detent portionsso spaced therealong as to be c'ooperable with said spring when saidauxiliary member is in looking or unlocking position, whereby saidauxiliary member is releasably retained in said positions until anexcess of force is exerted thereon in the direction in which it is to beslid, the degree to from said clamp being pressure applied thereby onsaid setting device.

3. In a tuning structure for a radio set, a slidable support, anadjustable setting device articu.--

which the screw depends adjustable to regulate the 2&559385 11 lat younte th eon a c amp er isuleiely un ed on id ort one' d o 'sc slams extndi t rd a d s tti dev ce a d anoth endthereoi having-a cam-engagingsurface of appreciable length. a screw threadedly received in'said oneend-extending therefrom toward said setting device; and adapted to exertlocking pres sur on said setting device when said clamp is appropriatelymoved, an auxiliary member include ing a pushbuttonoperatively connectedtoand movable with respect to said support and having acam-engageablewith the cam-engaging surface of said clamppthe end'of saidsurfa'cebeing so oriented with'respect tothe direction of movement ofsaid cam as to make a small acute'an'gle therewith, "saidauxiliarymember being movable relative'to said Support from an unlockingposi=tion,"in whiclrsaid cam is 'free of said cam-en gaging surface, througha starting locking position,'-in which said cam first engages the'enclof said cameengaging surface and; upon the exer tion of slight forceupon the pushbutton in its direction of movement, immediately and easilymoves said clamp so that said screw exerts lock ing'p'ressure uponsa'idsetting'device and to a full locking position; whichtlie action ofsaid cam on the length of 'said'cam-engaging' surface progressivelylocks said setting device in and more firmly, said other'en'do'f saidclamp' overlying said support-and being'engageable there with; and aleaf spring mounted on -sa'id support and having a portioniiiterposed'between said screw and said setting device, said springbeing biased to ur'g' e'said screw away from said' setting device, saidscrew beingadjus'table so as to press said leaf springlightly againstsaid setting de vice when said-auxiliary member is disengaged from saidclamp and when said other end of said clamp engages said support.'4;-The tu'ning structureof claim 2, in which said support-has aslotjsaid auxiliary member beingmounted ononeside'of said support andhaving a lug passing through saidslotand be-'- yond the'other sideojsaid support, and a spring score between said lugand'said other side ofsaidsupportso as to urgsaid lugaway therefl qmft l' by 'QflQ Q P iQ SaiX li ml m bet and said; s psor m desired spatial, relation their a l Ie t n tr cture f a m 2, wh ch i wetsu tsa o l a y. mem

beingmountedwn onejsid'e or said sup ort'and having-a lug passingthrough said slot and be yond'the other s ster said support, and aspring carried by said lug, -rri ovable'witll said auxiliary member, andactive between said lug andjsa'id other sideof said support so'asto urgesaid lug awaytherefromythfereby maintaining said auxil-- iary memberandsaid support in'desired spatial relationship;

"6. The" tuning structure of claim 2, in which said support hasa-slot,-said auxiliary member being mounted on one side? of said]support and having alugpass'in'g' through said' slot f and be yon'd theother side of said support; and aj sprin engaged by said lug at a pointspacedfromsaid other side'of said support and having ap ortionresiliently: engaging'said other side of said'sup; port, therebymaintaining said'au'xiliary member andsaidsupport in desired spatialrelationship. '7. The tuning structure of claim 2, in which having alugpassing throughsaid -slot and heyous the other side of said supportand-isprnig a r ed in said'lus at a point sp ced fmm said others de ofsai support mova le w th sa d auxiliary member, and having a portionresilient; 1y en a in said other side o a p r t erey ma nt imns said auxli r mem e and said su po in desir d sp tial relationship nd said u ortha in d test po io s spaced thereal ns so as to qo erab e with saidspring portion when sai au liary embe s. in l ck ng or unlocking po itiowhereby said auxiliary memb r is relcas hly retain d i said Positionsuntil an excess of force is exerted thereon in the direc on in whi h itis to he slid.

s. The tunin structure of claim 2, in which sa d sunporthas a slot. saidauxiliary m m r being mounted on one side of said support and havi g alug passin through said slot and beyond the other side of said support,and a spring carried by said lug at a point spaced from said other sideof said support, movable with said auxi iary member, and ha a port n rsiliently engaging said other side of said support, thereby maintainingsaid auxiliary member and said support in desired spatial relationship,and said support having an end surface and a groove spaced therefrom,said end surface and said groove definingv detent portons cooperablewith said spring portion.

9. In a tuning structure for a radio set comprising a sliclable membercarrying an adjustable setting device and'a releasable clamp active onsaid device to retain it in adjusted'position, and an auxiliary membermounted on said slidable member so as. to have a limited degree ofslidability relative thereto, operatively engageable with said clamp andmovable between a locking position in which it forces said'clamp againstsaid, device and an unlocking position in which said clamp is releasedfrom said device, the improvement which comprises one of 'said membershaving'a slot extending in the direction of relative motion of saidmembers, theother of said members having 9. lug passing through andbeyond, said. slot, and a spring active between said, lug and said oneof said members to'urg'e said lug away from said one of said members,thereby'maintaining 'said members in desired spatial relationship.

c 10, In a tuning structure for a radio set comprising a slidablemembercarryin'gan adjustable setting device and a releasable clamp active onsaid device to retain it in adjusted position, and an, auxiliary membermounted on said slidable member so as to have a limited degree of'slid{ability relative theretofoperativelyr engageable with saidclamp, andmovable between alocking position in which it'forces said clampa'gainst'said, device and: an unlocking position in which s id clampisreleasedifrom said device,'the im movement which comprises one of said membershaving a slot extending in the direction of rela tive motionofcsaid;me'mbers, the other or said members having a lug passing throughand beyond said: slot; and 'a" spring 'carried'by and movable withsaidllugan'd active between said lri'g andsaid orieof said members tourge said lug away from said one of said members, thereby maintaining'saidfmembers' in"desired spatial relationship. f"

11. In'a tuning structure for a radioset com prising a slidable membercarrying anadjustabiej setting device and a releasam clamp acti've pnsaid device to retain it in 'adjusted"positi on',' and; an auxiliarymemberinoiinted on said'slidable member'so "as 'to' "have a limiteddegree" of slidability relative thereto, operatively engageable withsaid clamp, and movable between a locking position in which it forcessaid clamp against said device and an unlocking position in which saidclamp is released from said device, the improvement which comprises oneof said members having a slot extending in the direction of relativemotion of said members, the other of said members having a lug passingthrough and beyond said slot, and a spring engaged by said lug at apoint spaced from said one of said members and having portionsresiliently engaging said one of said members at points on oppositesides of said lug in the direction of relative motion of said auxiliarymember, thereby maintaining said members in desired spatialrelationship.

12. In a tuning structure for a radio set comprising a slidable membercarrying an adjustable setting device and a releasable clamp active onsaid device to retain it in adjusted position, and an auxiliary membermounted on said support so as to have a limited degree of slidabilityrelative thereto, operatively engageable with said clamp, and movablebetween a locking position in which it forces said clamp against saiddevice and an unlocking position in which said clamp is released fromsaid device, the improvement which comprises one of said members havinga slot extending in the direction of relative motion of said members,the other of said members having a lug passing through and beyond saidslot, and a spring carried by said lug at a point spaced from said oneof said members, movable with said lug, and having a portion resilientlyengaging said one of said members, thereby maintaining said members indesired spatial relationship, and said one of said members having detentportions spaced therealong so as to be cooperable with said springportion when said auxiliary member is in locking or unlocking position,whereby said auxiliary member is releasably retained in said positionsuntil an excess of force is exerted thereon in the direction in which itis to be slid.

13. In a tuning structure for a radio set comprising a slidable membercarrying an adjustable setting device and a releasable clamp active onsaid device to retain it in adjusted position, and an auxiliary membermounted on said support so as to have a limited degree of slidabilityrelative thereto, operatively engageable with said clamp, and movablebetween a locking position in which it forces said clamp against saiddevice and an unlocking position in which said clamp is released fromsaid device, the improvement which comprises one of said members havinga slot extending in the direction of relative motion of said members,the other of said members having a lug passing through and beyond saidslot, and a spring carried by said lug at a point spaced from said oneof said members, movable with said lug, and having a portion resilientlyengaging said one of said members, thereby maintaining said members indesired spatial relationship, and said one of said members having an endsurface and a groove spaced therefrom, said end surface and said groovedefining detent portions cooperablewith said spring portion when saidauxiliary member is in locking or unlocking position, whereby saidauxiliary member is releasably retained in said positions until anexcess of force is exerted thereon in the direction in which it is to beslid.

' EARL H. ALLEN.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,401,744 Watson Dec. 2'7, 1921 1,454,238 Kaufman May 8,19232,233,330 Tyzzer Feb. 25, 1941 2,301,090 Teaf Nov. 3, 1942

